Potential energy surface and dissociative cleavage of chlorobenzene radical anion

Potential energy surface (PES) of the short-lived PhCl- radical anion has b een studied by ROHF/6-31+G* and MP2/6-31+G*//ROHF/6-31+G* calculations. The PES peculiarities were found to result from two reasons: (a) the quasi-deg eneracy of PhCl- pi states; (b) the presence of a low-lying repulsive sigma term. The anion meta-stable (2)Pi state has been located, and transition s tate for C-Cl cleavage has been found revealing an asymmetrical non-planar structure. Possible mechanisms of halobenzene anions dissociative cleavage are discussed, with the PhCl- as a model. (C) 2001 Elsevier Science B.V. Al l rights reserved.